Among the conventionally-known snow removal machines are snow removal machines which include a snow discharge member (snow blade) provided on a front section of a machine body, and auger type snow removal machines which throw accumulated snow by means of a snow throwing section. The auger type snow removal machines gather accumulated snow by means of an auger provided on a front section while traveling forward and can throw away the gathered snow by a blower through a chute. A chute guide, which is a vertically pivotable member for adjusting a snow throwing angle in a vertical or up-down direction, is provided on a distal end portion of the chute. The chute and the chute guide are components of the snow throwing section.
In ordinary auger type snow removal machines, a human operator adjusts a snow throwing direction and snow throwing distance of the chute in accordance with situations of an area where snow removal work is to be performed. If a place to which snow is to be thrown (snow throwing place) is large, the human operator does not have to frequently adjust the chute and the chute guide. However, if the snow throwing place is small, or if the thrown snow is to be gathered in one place, the human operator has to frequently adjust the chute and the chute guide, and such frequent adjusting operation is very bothersome. Besides, because the human operator has to frequently adjust the snow throwing direction while moving the snow removal machine forward, the adjusting operation would become a great burden on the human operator.
In view of the above, a technique for automatically adjusting the snow throwing direction of the chute and the chute guide in accordance with a traveled distance of the snow removal machine with a view to gathering thrown snow in one place is proposed in Japanese Utility Model Application Laid-open publication No. HEI-2-136122. In the snow removal machine disclosed in the HEI-2-136122 publication, a human operator first operates the chute and the chute guide to set a target snow throwing position by operating the chute and the chute guide, and then a control section automatically adjusts the snow throwing direction of the chute and the chute guide in such a manner as to maintain the target snow throwing position. More specifically, the control section adjusts the snow throwing direction of the chute and the chute guide on the basis of respective angles of the chute and the chute guide, traveled distance of the snow removal machine and a steering angle of a steering handle of the machine.
The ground surface on which to perform snow removal work is not always horizontal, and thus, the snow removal machine may sometimes perform the snow removal work while traveling on a sloping surface. As the snow removal machine itself inclines, the snow throwing direction of the chute and the chute guide too varies. Thus, even if the control section automatically adjusts the snow throwing direction of the chute and the chute guide, thrown snow cannot be gathered in one place. Therefore, a further improvement is yet to be made in order to alleviate the burden on the human operator.